Ink jet printers form images on paper by ejecting ink droplets from an array of nozzles on a print head. During the operational lifetime of an ink jet print head, the nozzles can become clogged, thus blocking the ejection of ink from the nozzles. Although most current ink jet printers include mechanisms for clearing clogged nozzles, these mechanisms are not always successful, and nozzles remained clogged.
Generally, when printer driver software generates print data to be sent to the print head, the software typically assumes that all of the nozzles of the print head are functioning properly. Thus, the print data may address nozzles that are malfunctioning. If this is the case, pixels that should be printed by the malfunctioning nozzles will remain blank on the paper. The typical result is an unwanted horizontal strip of white space in a printed image. As more and more nozzles malfunction during a print head's lifetime, this situation becomes more and more noticeable in printed output.
Therefore, a system is needed for identifying malfunctioning ink jet nozzles and providing this information to a printer driver so that the printer driver can compensate for the malfunctioning nozzles when generating print data.